Field of the Invention
The present invention, in some embodiments thereof, relates to devices and methods for initiating and/or sustaining minimal function of at least a portion of the gastrointestinal (“GI”) tract, and in particular to devices and methods for generating movement in one or more GI organs, optionally including at least esophageal motility.
Description of the Related Art
Unconscious and anesthetized patients are subject to loss of GI tract function, and specifically GI muscular motility and peristalsis. When patients are in such a condition for prolonged periods (e.g., hours, days or longer) their body cannot properly transfer and digest incoming food, even under external feeding regimes. Therefore, the ability to maintain normal levels of nutrition, immunity, and the ability to fight infections decrease over time. Patients may also encounter long-term deterioration of the GI tract or portions thereof. Additionally or alternatively, patients (e.g., gastroparesis patients) may need to stimulate the GI tract or portions thereof in order to increase current function levels, optionally for rehabilitation of GI tract or as a permanent modifier.
Peristalsis is a sequential, coordinated, contractions wave that travels through portions of the GI tract, such as the esophagus, and the intestines, propelling intraluminal contents distally (generally from mouth to anus). Primary peristalsis is the peristaltic wave triggered by the swallowing center. The peristaltic contractions wave travels at a speed in the order of magnitude of 2 cm/s. The secondary peristaltic wave is induced by esophageal distension from the retained bolus, refluxed material, or swallowed air, with the primary role to clear the esophagus of retained food or any gastroesophageal refluxate. Tertiary contractions are simultaneous, isolated, dysfunctional contractions. Anesthetization, sedation, analgesia, and traumatic events to the body (e.g., shock or surgery) are suspected of causing dysfunction of esophageal peristaltic motility. Hence, gastric content tends to not be transferred distally into the intestine and is even prone to travel up the esophagus, sometimes even all the way to the oral cavity, from where it may infiltrate the respiratory tract.
The esophagus is a tubular muscular organ having a length of approximately 25 cm, located between the upper esophageal sphincter (“UES”) and the lower esophageal sphincter (“LES”). The esophagus functions solely to deliver food from the mouth to the stomach using peristaltic muscle motion. Gastric contents refluxing through the esophagus are known to affect conditions which may increase morbidity and mortality rates. Gastroesophageal Reflux (“GER”) is a condition, in which the LES opens spontaneously, for varying periods of time, or does not close properly and stomach contents rise up into the esophagus. In Laryngopharyngeal Reflux (“LPR”), the retrograde flow of gastric contents reaches the upper aero-digestive tract. In order to diminish and treat such conditions, efforts have been made to develop medical and surgical means for improving LES functionality and for creating a substitute sphincter proximally adjacent the stomach. In some occasions it may be advantageous to develop a second “line of defense” provided proximally to the LES along the esophagus, especially to push back any gastric contents or chyme that infiltrated the LES or any substitute or supplement thereof. Such a need may arise, for example, in cases of intubation and/or ventilation, usually in anesthetized ICU patients, CVA patients, or others, in which esophageal motility is muted or less dominant.
Tubefeeding (e.g., “gastric feeding” or “enteral feeding”) is a common and life preserving procedure, however complications can arise. GER is commonly associated with tubefeeding, including in usage of nasogastric tubing (“NGT”) and other gastric feeding practices. Research in past years has discussed the emergence of GER as an effect of the use of NGT (see for example in Ibanez et al., “Gastroesophageal reflux in intubated patients receiving enteral nutrition: effect of supine and semirecumbent positions”, JPEN J Parenter Enteral Nutr. 1992 September-October; 16(5):419-22; in Manning et al., “Nasogastric intubation causes gastroesophageal reflux in patients undergoing elective laparotomy”, Surgery. 2001 November; 130(5):788-91; and in Lee et al., “Changes in gastroesophageal reflux in patients with nasogastric tube followed by percutaneous endoscopic gastrostomy”, J Formos Med Assoc. 2011 February; 110(2):115-9).